Olive & Olives

First cold pressing

The traditional method of producing olive oil

Harvesting the olives
Washing the olives and removing the leaves

Method of extraction

Triturating the olives

The olives are placed in a large basin made of granite or stainless steel. Millstones rotate around the basin, grinding the olives into a paste of pulp, water, oil and solid materials from the olive pits. All of this is done in the open air, which causes oxidation before the olives are pressed.

First cold pressing

The olive paste is placed onto fiber disks, which are stacked in columns. In years gone by, the disks were made of coconut husk, but today synthetic fibers are used. Pressure is applied to the disks and liquid is separated from the paste. The liquid contains both oil and water and must be decanted to separate the oil. A more modern method uses a centrifuge to separate the oil from the water.

A second pressing may also be done with hot water to help extract the oil from the paste, however the heat causes deterioration of the oil so this method is only used for cooking oil; not for oils intended to be served raw, on bread or salads.

Decanting

Why do we seldom see the term “first cold pressing” on bottles any more?

Cold pressing is rarely used these days, be it in commercial or artisanal production. Numerous studies have shown that the quality of oil improves when the oil is obtained through extraction.

You still see the traditional mills with their millstones, but these are more for the interest of tourists than anything else. Today, olive oil production relies on mixers and centrifuges and the term most commonly seen on bottles is “cold extraction.”

Cold extraction

Harvesting the olives
Washing the olives and removing the leaves

Extraction process

Triturating the olives

The olives are placed in basins where they are crushed by hammers into a mixture of pulp, water, oil and solid matter from the pits.

A maximum temperature of 28º C is permitted to extract the extra virgin olive oil. At that temperature, the producer is assured of getting the most oil out of the fruit, without altering the taste or nutritional value of the olive.

Horizontal centrifuge
Separates the solids and liquids

Vertical centrifuge
Separates the liquids: water and oil

Filtration
(At the producer’s discretion)

Decanting

Classifications of olive oil

This is the step at which the olive oil is classified according to the standards set by the International Olive Council.
1. Extra virgin olive oil
2. Virgin olive oil
3. Ordinary olive oil
4. Lampante virgin olive oil
5. Refined olive oil
6. Olive oil (a mixture of virgin and refined olive oils)
7. Olive-pomace oil

The two methods used to analyze and verify the classification of the oil are:
1. Physical-chemical analysis
2. Organoleptic evaluation (using the senses)

Decanting

Bottling